Application of Nonlinear Models Combined with Conventional Laboratory Indicators for the Diagnosis and Differential Diagnosis of Ovarian Cancer.

Existing biomarkers for ovarian cancer lack sensitivity and specificity. We compared the diagnostic efficacy of nonlinear machine learning and linear statistical models for diagnosing ovarian cancer using a combination of conventional laboratory indicators. We divided 901 retrospective samples into an ovarian cancer group and a control group, comprising non-ovarian malignant gynecological tumor (NOMGT), benign gynecological disease (BGD), and healthy control subgroups. Cases were randomly assigned to training and internal validation sets. Two linear (logistic regression (LR) and Fisher's linear discriminant (FLD)) and three nonlinear models (support vector machine (SVM), random forest (RF), and artificial neural network (ANN)) were constructed using 22 conventional laboratory indicators and three demographic characteristics. Model performance was compared. In an independent prospectively recruited validation set, the order of diagnostic efficiency was RF, SVM, ANN, FLD, LR, and carbohydrate antigen 125 (CA125)-only (AUC, accuracy: 0.989, 95.6%; 0.985, 94.4%; 0.974, 93.4%; 0.915, 82.1%; 0.859, 80.1%; and 0.732, 73.0%, respectively). RF maintained satisfactory classification performance for identifying different ovarian cancer stages and for discriminating it from NOMGT-, BGD-, or CA125-positive control. Nonlinear models outperformed linear models, indicating that nonlinear machine learning models can efficiently use conventional laboratory indicators for ovarian cancer diagnosis.

Liquid-Metal-Induced Hydrogen Insertion in Photoelectrodes for Enhanced Photoelectrochemical Water Oxidation.

Fast charge separation and transfer (CST) is essential for achieving efficient solar conversion processes. This CST process requires not only a strong driving force but also a sufficient charge carrier concentration, which is not easily achievable with traditional methods. Herein, we report a rapid hydrogenation method enabled by gallium-based liquid metals (GBLMs) to modify the prototypical WO3 photoelectrode to enhance the CST for a PEC process. Protons in solution are controllably embedded into the WO3 photoanode accompanied by electron injection due to the strong reduction capability of GBLMs. This process dramatically increases the carrier concentration of the WO3 photoanode, leading to improved charge separation and transfer. The hydrogenated WO3 photoanode exhibits over a 229% improvement in photocurrent density with long-term stability. The effectiveness of GBLMs treatment in accelerating the CST process is further proved using other more general semiconductor photoelectrodes, including Nb2O5 and TiO2.

Phase change composites of octadecane and gallium with expanded graphite as a carrier.

Phase change materials (PCMs) have attracted more and more attention in the field of energy and thermal management due to the characteristic of exchanging heat with small temperature change. In order to obtain perfect PCMs, previous researchers usually prepared various phase change composites (PCCs), but there is still a gap toward the goal. Perhaps the development of PCMs with adjustable properties in a wide range to meet different needs is a feasible option. Given that the properties of organic PCMs and metal PCMs are highly complementary, using expanded graphite (EG) as a mediator, a stable PCC of octadecane and gallium that are difficult to directly mix, was successfully prepared. Octadecane and gallium are stored in the microstructures of EG, and the microstructures of EG play the role of storing nucleation embryos, and the suppression of supercooling can reach more than 86.82%. The test results showed that the properties of the PCC are indeed a balance between octadecane and gallium, and can be adjusted in a wide range. The PCC also has good structural and chemical stability, which can effectively avoid the corrosion risk caused by gallium leakage. The PCC samples containing equal amounts of gallium and paraffin were selected for thermal management performance tests. The results indicated that the PCC has application potential in related fields, and can provide a reference for the development of other PCCs.

Programmable protein topology via SpyCatcher-SpyTag chemistry in one-pot cell-free expression system.

Protein-based biomaterials play a significant role in biomedicine and biocatalysis due to their intrinsic biocompatibility and biodegradability. Topological biomaterials show certain advantages without changing the wild-type sequence of the protein, such as unique biofunctions and exceptional stabilities. However, the tuning for the synthesis and assembly of topological protein materials was limited. In this study, we combined the SpyCatcher/SpyTag (SC/ST) chemistry and proposed a cell-free one-pot transcription-translation-assembly system for flexibly regulating the production of topological protein materials. Dimers, trimers, and multimers of proteins with topological structures were designed. Next, the cell-free system was optimized by adjusting the magnesium ion concentration and the molar ratio of different plasmids to obtain the greatest degree of polymerization. The optimal Mg ion concentration was finally determined to be 15 mM, and their most appropriate plasmid molar ratios (SC:ST) were 7:3 for dimers, trimers, and multimers. Finally, based on the topological structure of the polymer, the function was verified with the fusion of xylanase, and it was found that the xylanase activity of the polymer was three times that of the xylanase monomer. Universally, the cell-free system in this study can be used to synthesize protein materials with different topologies based on various covalent or non-covalent methods, and it is likely to have potential in topological structure exploration and bioapplications.

Supramolecular protein assembly in cell-free protein synthesis system.

Protein-based biomaterials have the characteristics of stability and biocompatibility. Based on these advantages, various bionic materials have been manufactured and used in different fields. However, current protein-based biomaterials generally need to form monomers in cells and be purified before being assembled in vitro. The preparation process takes a long time, and the complex cellular environment is challenging to be optimized for producing the target protein product. Here this study proposed technology for in situ synthesis and assembly of the target protein, namely the cell-free protein synthesis (CFPS), which allowed to shorten the synthesis time and increase the flexibility of adding or removing natural or synthetic components. In this study, successful expression and self-assembly of the dihedral symmetric proteins proved the applicability of the CFPS system for biomaterials production. Furthermore, the fusion of different functional proteins to these six scaffold proteins could form active polymers in the CFPS system. Given the flexibility, CFPS is expected to become a powerful tool as the prototyping and manufacturing technology for protein-based biomaterials in the future.

Self-Assembled Copper Film-Enabled Liquid Metal Core-Shell Composite.

Liquid metal (LM) droplets covered with functional materials, especially metallic, often make breakthroughs in performance and functionality. In this study, self-assembly was used to synthesize copper films on the surface of LM. Herein, using CuO nanoparticles as the monomers, driven by the electrostatic interaction between CuO and eutectic gallium-indium (EGaIn) in the alkaline environment, EGaIn@Cu is realized by taking advantage of the reducing property of the EGaIn-alkaline interface. The copper film is smooth and dense, and under its protection, a layer of gallium oxide remains on the reaction interface between copper and LM, which enabled EGaIn@Cu to possess the volt-ampere curves similar to the Schottky mode, showing that the proposed mechanism has the potential to be used in the bottom-up synthesis of the semiconductor junction. Owing to the support of the copper film, the stiffness coefficient of the LM droplet can be increased by 56.9%. Coupled with the melting latent heat of 55.46 J/g and the natural high density of metal, EGaIn@Cu is also a potential phase change capsule. In addition, a method based on stream jetting and self-breaking up mechanisms of LM to batch-produce sub-millimeter capsules was also introduced. The above structural and functional characteristics demonstrate the value of this work in related fields.

Hydrochromic Visualization of a Keggin-Type Structure Triggered by Metallic Fluids for Liquid Displays, Reversible Writing, and Acidic Environment Detection.

Hydrochromic visualization of a liquid interface shows vital potential applications in liquid displays, reversible writing, and acidic environmental detection, which offers a platform for detection and forewarning due to its intuitive and visual characteristics. Herein, we report a hydrochromic display due to the interfacial effect of liquid metal (LM)-triggered ammonium metatungstate (AMT) with instant dual-mode color switching. The double-electron-transfer reaction of the AMT on the surface of gallium-based LM caused the formation of heteropoly blue in the presence of acidic surroundings, resulting in a reversible color switching from being colorless to blue or blue to colorless. This visual interfacial discoloration phenomenon can be applied to the liquid display on diverse patterns of the LM surface. Furthermore, papers with a functional display were prepared, which can be used for writing up to eight times with dual-mode color switching. In addition, the reactive activity of acid triggering make it a potential candidate for use in visualizing an acidic environment with a detection range of pH = 1 to 0 (0.1-1.5 M). Briefly, this interfacial discoloration phenomenon enriches the interfacial engineering of LM and provides a unique prospective and wide-range platform for the application of LM.

Comparison of the osteoblastic activity of low elastic modulus Ti-24Nb-4Zr-8Sn alloy and pure titanium modified by physical and chemical methods.

Ti-24Nb-4Zr-8Sn (Ti2448) alloy is a novel low elastic modulus ß-titanium alloy without toxic elements. It also has the advantage of high strength, so it has potential application prospects for implantation. To develop its osteogenic effects, it can be modified by electrochemical, and physical processes. The main research aim of this study was to explore the bioactivity of Ti2448 alloy modified by sandblasted, large-grit, acid-etched (SLA), micro-arc oxidation (MAO) and anodic oxidation (AO), and to determine which of the three surface modifications is the best way for developing the osteogenesis of bone marrow mesenchymal stem cells (BMMSCs). In vitro studies, the cytoskeleton, focal adhesion and proliferation of BMMSCs showed that both pure titanium and Ti2448 alloy have good biocompatibility. The osteogenic differentiation of BMMSCs with the Ti2448 alloy were examined by detecting alkaline phosphatase (ALP), mineralization nodules and osteogenic proteins and were better than that with pure titanium. These results showed that the Ti2448 alloy treated by SLA has a better effect on osteogenesis than pure titanium, and AO is the best way of three surface treatments to improve osteogenesis in this study.

Recoverable Liquid Metal Paste with Reversible Rheological Characteristic for Electronics Printing.

Gallium-based liquid metals are applied in the fabrication of soft electronics because of their conductivity and flexibility. However, the large surface tension and weak adhesion of liquid metals limit the available printing substrates. Recent researches indicate that amalgamating metal particles can turn liquid metal from fluid into a paste which has superb electrical conductivity, plasticity, and strong adhesion to substrates. In this work, a recoverable liquid metal paste was made by mixing eutectic Ga-In alloy and nonmetallic SiO2 (quartz) particles (Ga-In-SiO2 paste, called GIS). GIS has excellent conductivity and printable properties similar to those of previously reported liquid metal pastes. Furthermore, the bonding between Ga-In alloy and quartz particles is reversible. In acidic or alkaline solution, Ga-In alloy can be separated from quartz particles and agglomerated to bulk by stirring. Moreover, the study of the mechanism of adhesion behavior suggests that extruding fresh liquid metal droplets to form more oxide and shearing friction are the critical factors for adhesion. This work proposed a new liquid metal paste with a reversible rheological property and promoted the understanding of the working principle of liquid metal paste.

Large-Magnitude Transformable Liquid-Metal Composites.

Most of the existing robots would find it difficult to stretch and transform all parts of their body together due to rigid components and complex actuation mechanisms inside. Here, we presented a highly transformable liquid-metal composite (LMC) that is easy to change shape in large magnitude and resume its original state again according to need. When subject to heating, part of the ethanol droplets embedded in the composite would change phase and then actuate. We demonstrate the flexible transformation of LMC-made octopus from a two-dimensional shape into several predictable three-dimensional shapes freely on a large scale (even up to 11 times its initial height) through remote wireless heating, which needs no sophisticated operating system at all. Further, several designed behaviors, such as movement of octopus and entangling objects of soft robots, are also realized. Theoretical analysis of the heating-induced liquid-vapor transition of the embedded ethanol droplet interprets the mechanisms involved. The present findings open a new way to fabricate functional transformable composites that would find significant applications in developing future generation soft robots.

Discoloration Effect and One-Step Synthesis of Hydrogen Tungsten and Molybdenum Bronze (H x MO3) using Liquid Metal at Room Temperature.

This paper presents a new route to one-step fabrication and in situ application of hydrogen tungsten and molybdenum bronze (H x MO3) at room temperature and triggers the interdisciplinary research of multifunctional materials between liquid metal and transition-metal oxides (TMOs). Gallium-based liquid metal (GBLM) enables the discoloration effect on TMOs in acid electrolytes at ambient temperature. The underlying mechanism behind this phenomenon can be ascribed to the redox effect at the interface of liquid metal and TMOs in acid electrolytes. Both the theoretical calculations and the experimental results demonstrate that the increasing intercalation of H+ ions into the lattice of WO3 raises the electron density at the Fermi level and charge carriers. H+ ion content in the obtained H x MO3 can be controlled in our approach to meet different requirements. Taking advantage of the one-step fabrication and room-temperature liquid phase nature of the liquid metal, H x MO3 is synthesized under ambient conditions in a very short time, which is inaccessible with conventional solution-processed mechanical alloying, or other methods. The H x MO3 obtained in this one-step approach enables convenient and simple applications for biomimetic camouflage, cost-effective energy storage, H+ ion sensor, and electronic switch.

A Highly Stretchable Liquid Metal Polymer as Reversible Transitional Insulator and Conductor.

Materials with a temperature-controlled reversible electrical transition between insulator and conductor are attracting huge attention due to their promising applications in many fields. However, most of them are intrinsically rigid and require complicated fabrication processes. Here, a highly stretchable (680% strain) liquid metal polymer composite as a reversible transitional insulator and conductor (TIC), which is accompanied with huge resistivity changes (more than 4 × 109 times) reversibly through a tuning temperature in a few seconds is introduced. When frozen, the insulated TIC becomes conductive and recovers after warming. Both the phase change of the liquid metal droplets and the rigidity change of the polymer contribute directly to transition between insulator and conductor. A simplified model is established to predict the expansion and connection of liquid metal droplets. Along with high stretchability, straightforward fabrication methods, rapid triggering time, large switching ratio, good repeatability, the TIC offers tremendous possibilities for numerous applications, like stretchable switches, semiconductors, temperature sensors, and resistive random-access memory. Accordingly, a system that can display numbers and letters via converting alternative TIC temperature to a binary signal on a computer is conceived and demonstrated. The present discovery suggests a general strategy for fabricating and stimulating a stretchable transitional insulator and conductor based on liquid metal and allied polymers.

Self-Growing and Serpentine Locomotion of Liquid Metal Induced by Copper Ions.

The realization of serpentine locomotion has been a core goal pursued. Here, a straightforward approach was discovered to generate the serpentine locomotion based on a brand-new phenomenon observed on liquid metal (Ga67In21Sn12). The dynamic process that liquid metal can automatically produce and move like tremendous slim snakes was revealed and the underlying mechanisms were clarified and interpreted. It was found that the self-growing serpentine locomotion of liquid metal is driven by the localized surface pressure difference related to the unbalanced surface tension. The present work offers new insight and forms in developing future autonomous soft systems and bionic multifunctional robots.

Metallic Bond-Enabled Wetting Behavior at the Liquid Ga/CuGa2 Interfaces.

Interface interaction can strongly modify contact angle, adsorption energy, interfacial tension, and composition of the contact area. In particular, the interfaces between gallium-based liquid metal (LM) and its intermetallic layer present many mysterious and peculiar wetting phenomena, which have not been fully realized up to now. Here in this study, we found that a gallium-based liquid metal droplet can quickly transform into a puddle on the CuGa2 surface through a spreading-wetting procedure. The mechanism lying behind this phenomenon can be ascribed to the formation of an intermetallic CuGa2 on Cu plate surface, which provides a stable metallic bond to induce the wetting behavior. For a quantitative evaluation of the interface force, a metallic bond-enabled wetting model is established on the basis of the density functional theory. The first-principles density functional calculations are then performed to examine the work function, density of states, and adsorption energy. The predicted results show that the work function of CuGa2 (010) is approximately 4.47 eV, which is very comparable with that of pure liquid Ga (4.32 eV). This indicates that the valence electrons between Ga and CuGa2 slab can exchange easily, which consequently leads to the strong valence electron hybridization and metallic bond. In addition, the adsorption energy of a single Ga atom on CuGa2 (010) slab has a larger value than In and Sn. The tested metallic bond wetting force at the interface is proportional to the average adsorption energy of the gallium-based LM adatom, and increases with the rising content of gallium. The simulation results demonstrate excellent consistency with the experimental data in this work.

Improvement of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for identification of clinically important Candida species.

BACKGROUND: Matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) is emerging as a rapid and accurate tool for identifying pathogens. MALDI-TOF identification of Candida at the species level remains unsatisfactory because of an incomplete commercial database. METHODS: Using Bruker Daltonics MALDI Biotyper software, an in-house spectral database library was created with m/z ratios of 2,000 to 20,000 Da from 60 successfully identified clinical isolates of Candida spp. (6 species). It was incorporated into the original database to produce the augmented Bruker-Tianjin database. The augmented database was tested with 347 clinical isolates of 6 species comparing with Bruker database in parallel. RESULTS: The identification rates at the species level were 91.6% (318/347) using the Bruker database and 99.1% (344/347) for the Bruker-Tianjin database. CONCLUSIONS: Database expansion and refinement can easily and effectively improve MALDI-TOF MS performance for enhanced clinical pathogen identification.

Recent progress on RE2O3-Mo/W emission materials.

RE2O3-Mo/W cathodes were prepared by powder metallurgy method. La2O3-Y2O3-Mo cermet cathodes prepared by traditional sintering method and spark plasma sintering (SPS) exhibit different secondary emission properties. The La2O3-Y2O3-Mo cermet cathode prepared by SPS method has smaller grain size and exhibits better secondary emission performance. Monte carlo calculation results indicate that the secondary electron emission way of the cathode correlates with the grain size. Decreasing the grain size can decrease the positive charging effect of RE2O3 and thus is favorable for the escaping of secondary electrons to vacuum. The Scandia doped tungsten matrix dispenser cathode with a sub-micrometer microstructure of matrix with uniformly distributed nanometer-particles of Scandia has good thermionic emission property. Over 100 A/cm2 full space charge limited current density can be obtained at 950Cb. The cathode surface is covered by a Ba-Sc-O active surface layer with nano-particles distributing mainly on growth steps of W grains, leads to the conspicuous emission property of the cathode.